The Descent of Man, and Selection in Relation to SexDarwin, Charles
History
The Descent of Man, and Selection in Relation to Sex
Darwin, Charles
Evolution (Biology); Human beings -- Origin; Sex differences; Sexual dimorphism (Animals); Sexual selection in animals
nearly the same conclusion as that given here.), after collecting all
the known evidence on this head, concludes that the external shell is
of no distinct use. The ears of the chimpanzee and orang are curiously
like those of man, and the proper muscles are likewise but very
slightly developed. (30. Prof. A. Macalister, ‘Annals and Magazine of
Natural History,’ vol. vii. 1871, p. 342.) I am also assured by the
keepers in the Zoological Gardens that these animals never move or
erect their ears; so that they are in an equally rudimentary condition
with those of man, as far as function is concerned. Why these animals,
as well as the progenitors of man, should have lost the power of
erecting their ears, we cannot say. It may be, though I am not
satisfied with this view, that owing to their arboreal habits and great
strength they were but little exposed to danger, and so during a
lengthened period moved their ears but little, and thus gradually lost
the power of moving them. This would be a parallel case with that of
those large and heavy birds, which, from inhabiting oceanic islands,
have not been exposed to the attacks of beasts of prey, and have
consequently lost the power of using their wings for flight. The
inability to move the ears in man and several apes is, however, partly
compensated by the freedom with which they can move the head in a
horizontal plane, so as to catch sounds from all directions. It has
been asserted that the ear of man alone possesses a lobule; but “a
rudiment of it is found in the gorilla” (31. Mr. St. George Mivart,
‘Elementary Anatomy,’ 1873, p. 396.); and, as I hear from Prof. Preyer,
it is not rarely absent in the negro.
[Fig. 2. Human Ear, modelled and drawn by Mr. Woolner. The projecting
point is labelled a.]
Public-domain text, read in full here on John Shaqi.
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